Multiphysic design rules applied to inductors or transformers for railway application

Nowadays, power converters in the railway industries are increasingly more compact and powerful. This progress is due to the use of fast and efficient components capable of working at high frequency such as IGBT. However, this evolution leads to a considerable loss of harmonics in transformers and complicates their design. Moreover, the mean time between failures (MTBF) must be very long. This MTBF is linked to the results of thermal modeling that in turn has to be accurate. The model must also take into account the electronic switches used. This paper presents a multi-physic model including thermal and electromagnetic aspects. The simulations are successfully compared with experimental measurements. This model is then coupled to a mixed-variable constrained non-dominating sorting Genetic Algorithm (NSGA-II). Some optimization and sensitivity study results are presented.